I think the iff was intended by @kba because it's a logical term meaning "if and only if". But it confused others as well, so we might write it more explicitly (@kba)?

Yeah I was unsure about that too, but since this is in documentation and not actual code...let's see what @kba thinks.

Yeah, it was meant as "if and only if" - I like precise language :) But since it confuses you, let's drop it.